A number of factors can affect the quality and value of estate jewelry. The most important of these include beauty, materials, craftsmanship, condition, alterations, and rarity. The first three are the same as factors you’d consider or discuss for new jewelry. The last three are unique to estate pieces.

Beauty

Beauty is always a top consideration in both quality and value. Of course, it’s also a matter of personal taste. But regardless of jewelry’s period, form, or style, you can say that beauty generally means the overall proportioning of the design is attractive; the colors of the materials work together and are visually pleasing; the various parts or components are harmonious in size and style; and any technical or decorative details contribute to overall appeal.

Materials

The materials from which a piece is made obviously affect its value – 14K vs. 18K gold, ruby vs. red garnet, and so forth. In some cases, they relate to quality too. For example, most people would agree that a natural, untreated sapphire with fine color and high clarity represents an exceptional level of quality.

Craftsmanship

This is another factor that counts in both quality and value. In well-made jewelry, all the components fit together smoothly, and any mechanical parts – clasps, links, hinges, etc –function as they should. The surface is entirely polished or textured, details are well defined, and the inside or back is finished as well as the top or front.

Condition

Estate jewelry usually shows signs of wear. The older a piece is, the more obvious these are likely to be. Most people would say that minor age-related blemishes add “character” and “charm” to an estate piece. But condition issues that negatively affect beauty or wearability also reduce quality and value. Examples include thin shanks, bent prongs, broken clasps, missing gems, and pitted, cracked, or discolored metal.

Alterations

These are also common with estate jewelry. Most can be classified as repair, remodeling, or adaptation. The first category includes steps that have been taken to correct significant condition problems. Remodeling involves procedures like turning a pendant into a ring (or vice versa). Adaptation covers minor jobs such as replacing screw backs with posts, so earrings can be worn in pierced ears. As you might expect, the effect alterations have on quality and value largely depends on how well they were done.

Rarity

You can think of this as supply versus demand. It has more to do with value than quality, and it’s the most complicated of all the factors on this list. Rarity partly depends on how much of a certain form or style was produced in a given period. But it also involves how many of those pieces have survived, and how much customers want them. It’s possible for items that are rare to be low in value because there’s little demand for them, or for more abundant items to have high value because the demand for them is also high.

When you put all these factors together, it’s easy to see why quality and value can become a complicated topic for estate jewelry. But for devoted collectors of this category, that’s actually part of the interest, appeal, and fun.